الفهرس 
Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
The present thesis is divided into two parts. The first parts concern (Characterization and physical properties of polyurethane/Polyvinyl chloride (PU/PVC) polymer blends) to obtain the optimum concentration suitable for the suggested application by studying some physical properties of the PU/PVC polymer blends prepared by casting technique. Structural, optical, thermal and mechanical properties of polymer blend have been studied using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Ultraviolet Visible (UV/Vis.), Differential scanning calorimetry (DSC), Thermogravimetric (TGA), and mechanical properties (stress–strain curve). XRD showed two peaks at 2θ =21.6°and 24° increase amorphous nature with addition of PVC. The FTIR spectra showed some limited changes in the IR absorption bands. This reveals an interaction between PU and PVC. UV/Vis. spectroscopic analysis indicated that an absorption band centered around 279 nm, which is characteristic of PU and related to carbonyl groups(C = O), confirmed in FTIR at about 1735 cm-1 band which assigned to transition and the sharp edge in the range of 208–280 nm, is shifted toward the longer wavelength with increasing PU concentration. Differential scanning calorimetry (DSC) results was observed a single glass transition temperature (Tg) for blends this confirming existence miscibility within the blends. The causes for best thermal stability of some blends may be described by measurements of interactions between C=O groups of PU and the α-hydrogen of PVC or a dipole–dipole –C=O..Cl–C– interactions. TGA suggested that the thermal stability increases with increasing PU concentration. All techniques demonstrate the complexation between PU and PVC and the best or optimum concentration of PU/PVC is (75/25 wt. %).The second part entitled ”Multi –walled carbon nano tubes (MWCNTs) filled with different concentration wt% were added to the optimum concentration of the blend to study the effects of it on some physical properties (mechanical and electrical properties) of PU/PVC polymer blend to use in in electronic applications”. Various concentrations 0.01, 0.02, 0.04 and 0.06 wt. % of MWCNTs were added to the optimum concentration of PU/PVC (75/25 wt.%) and prepared by casting technique using high prop sonicator for good dispersion of MWCNTs. The prepared films were investigated by different techniques to study the effect of the reinforcing filler (MWCNTs) on the structural, thermal, mechanical and electrical properties of the polymer blend. X–ray analysis revealed the semi crystallinity of the PU/PVC-MWCNTs nanocomposites decreases with increasing MWCNTs content, due to the change in the crosslink density of PU/PVC after the addition of MWCNTs. There are some changes in the IR absorption band positions and its intensities this indicate the interaction between the polymer blend and MWCNTs. UV-Vis analysis revealed that the values of the optical energy gap are decrease with increasing filler concentration this indicates that there is a charge transfer complexes arises between the polymer blend and MWCNTs, which confirm that the addition of MWCNTs can improve the electrical properties of the polymer blend. Scanning electron microscopy observation indicated that a homogeneous dispersion of MWCNTs throughout Polymer matrix and a strong interfacial adhesion between MWCNTs and the polymer matrix was achieved in PU/PVC-MWCNTs nanocomposites. Differential scanning calorimetry (DSC) indicates that adding MWCNTs increase in the melting temperature (Tm) and degradation temperature (Td) the thermal stability of the composites. The thermogravimetric analysis (TGA) showed the decomposition of nanocomposites is shifted towards higher temperature due to the thermal stability enhancement after addition of the SWCNTs. Mechanical analysis show that incorporation of MWCNTs improving the mechanical properties as both the tensile stress and elastic modulus of the nanocomposites increase with increasing filler concentration, which means that addition of MWCNTs can improve the mechanical properties of the composites. All techniques demonstrate that the addition of MWCNTs to the polymer blends can improve the thermal, mechanical and electrical properties of the composites comparing to the pure polymer blend.The Third part entitled ”Single–walled carbon nanotubes (SWCNTs) filled with different concentrations (same concentrations in MWCNTs) were added to the optimum concentration of the blend to study the effects of it on some physical properties (mechanical and electrical properties) of PU/PVC polymer blend to use in in electronic applications. The prepared films were investigated by different techniques to study the effect of the reinforcing filler (SWCNTs) on the structural, thermal, mechanical and electrical properties of the polymer blend. The X-ray indicate decreasing in semi crystallinity after adding SWCNTs to PU/PVC. The FT-IR spectra confirmed presence interaction between CNTs and pure PU/PVC. The SEM indicated that a homogeneous dispersion of SWCNTs throughout Polymer matrix. The DSC and TGA confirmed the thermal stability of the samples after addition of the SWCNTs to the pure PU/PVC and the activation energy was decreased. Mechanical properties improved due to adding of the SWCNTs to pure polymer blend better when added the MWCNTs to pure PU/PVC so according to all that results these nanocomposites (PU/PVC-MWCNTs) may be the candidate to use in wind turbine blade applications.The ac conductivity was found to increase with the increase of both the temperature and the frequency, and follows the power low. The frequency exponent s was found to decrease with the increase of temperature. The correlated barrier hopping (CBH) model was found to be applying to the ac conductivity data. The observed properties of the prepared nanocomposites (PU/PVC-MWCNTs) better when use the PU/PVC-SWCNTs so according to all that results this nanocomposites (PU/PVC-MWCNTs) may be candidate to use in many in electronic applications such as separator in batteries, storage devices, and also in thermo-electric devices which deserves further investigation.